The present invention relates to a vehicular headlamp in which a semiconductor light-emitting element such as a light-emitting diode or the like is used as a light source, as well as to a method for manufacturing such a headlamp.
An incandescent bulb or a discharge bulb has commonly been used as a light source of a vehicular lamp. More recently, a light-emitting element such as a light-emitting diode (LED) in which a semiconductor is used has been investigated for the purposes of reducing electric power consumption, reducing the size of the lamp, and the like.
For example, a high-mount stop lamp, a rear side marker lamp or the like are as examples of lamps in which an LED light source is used.
Special optical design techniques are required in order to create a low-beam light distribution pattern if a light-emitting element such as an LED is employed as a light source of a vehicular headlamp. For example, a lamp structure is known in which switching is allowed for various illuminating functions by way of a plurality of semiconductor light sources which are arranged in a matrix and selectively activated as required for a given function. (For example, refer to Japanese Laid-Open Application Publication No. 2001-266620, particularly FIGS. 1 and 4.)
In a vehicular headlamp, however, positional accuracy of optical components is important because a light-emitting element and component parts of the optical system are at a close distance. In a conventional light-emitting element, however, often the positional accuracy of thesemiconductor chip of the light-emitting element with respect to the reflector or lens of the optical system is sufficiently low as to have a significant adverse effect on the formation of the headlamp light distribution. In a low-beam light distribution pattern, for example, it becomes difficult to form consistently and accurately a clear cut line or a cut-off line which define a contrast boundary.